The present invention relates to a seat belt buckle. Seat belt buckles have been available for very many years now and are now rather sophisticated and complicated mechanisms. Several types of buckle include a frame, and a tongue adapted to be carried on the seat belt and slidably insertable into the frame along a planar path.
An ejector is provided which is spring urged to be able to push the tongue out again at an appropriate moment.
Various different forms of locking mechanisms are provided which are usually very complex and therefore rather expensive to manufacture. For example, U.S. Pat. No. 4,100,657 discloses a buckle in which insertion of the tongue in one direction against the bias of the ejector is associated with motion of a release button in the opposite direction. A ramp on the release button forces a roller into an opening in the tongue. This mechanism requires the co-ordinated motion of the ejector and release button. The inclination of the ramp is also such that even when the buckle and tongue are under load, a slight pressure on the release button will eject the tongue.